Professor Daniel A. Vallero is an internationally recognized author and expert in environmental science and engineering. He has devoted decades to conducting research, teaching, and mentoring future scientists and engineers. He is currently developing tools and models to predict potential exposures to chemicals in consumer products. He is a full adjunct professor of civil and environmental engineering at Duke University's Pratt School of Engineering. He has authored 20 environmental textbooks, with the most recent addressing the importance of physical principles in environmental science and engineering. His books have addressed all environmental compartments and media within the earth's atmosphere, hydrosphere, lithosphere, and biosphere.